Sometimes drugs are not safe when you take them with certain other drugs. Taking them together can cause bad side effects. This is one of those drugs. Be sure to talk to your doctor about all the drugs you take.

Avoid

If you have an allergy to methenamine or any other part of this drug.

Tell your doctor if you are allergic to any drugs. Make sure to tell about the allergy and what signs you had. This includes telling about rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.

If you have any of these health problems: Kidney disease, very bad fluid loss, or very bad liver disease.

Precautions

Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.

If you are allergic to tartrazine, talk with your doctor. Some products have tartrazine.

If you have liver disease, talk with your doctor.

Check all drugs you are taking with your doctor. This drug may not mix well with some other drugs.

You may need to check the acid content (pH) of your urine using a dipstick test.

Do not take aspirin, antacids, or drugs that raise the pH of the urine while on this drug.

Avoid citrus fruits, dairy products, and some veggies while taking this drug.

Some types of water pills may lower the effects of this drug. Talk with the doctor.

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.